GEOGRAPHY MYP/GCSE/DP
  • Home
    • Contact
  • MYP
    • Development >
      • An unequal world?
      • Billionaires investigation
      • Africa: the danger of a single story
      • Patterns of development
      • Trade and development
      • Fair Trade
      • Sustainable Development Goals
    • Tectonic Hazards >
      • What is risk?
      • Alfred Wegener and Continental Drift
      • Plate tectonics
      • Distribution of tectonic hazards
      • Measuring earthquakes
      • Why do people die in earthquakes?
      • School earthquake plan
      • Earthquake assessment
      • Volcanoes - what are they? Why are they important?
      • Volcano "Science Fair"
      • Causes of tsunami
    • Population >
      • Why study population?
      • Population distribution
      • Population growth
      • Population pyramids
      • Demographic transition model
      • Migration
      • Migration examples - case studies
      • Refugees in Indonesia
      • Population revision activities
    • Weather and Climate >
      • Weather vs Climate and why is it important?
      • Climate graphs
      • Why does it rain?
      • What affects temperature and why is Jakarta so hot and wet?
      • What causes wind and how do we measure it?
      • Microclimates
  • IGCSE
    • Course information
    • Physical: Hazardous environments >
      • Distribution of tectonic hazards
      • Causes of tsunami
      • Measuring earthquakes
      • Earthquake case study 1: Haiti
      • Earthquake case study 2: Christchurch
      • Why do earthquakes do more damage in LICs than in HICs?
      • How are volcanic eruptions measured?
      • Tropical storms - distribution
      • Causes of tropical cyclones
      • Tropical cyclones - case study
      • Why live in hazardous areas?
    • River Environments >
      • Hydrological cycle
      • River basins
      • Factors affecting river regimes
      • Fluvial processes: erosion
      • Fluvial processes: weathering and mass movement
      • Fluvial processes: transportation and depositon
      • River features and their formation
      • How rivers change from source to mouth
      • Uses of water
      • Water pollution
      • Water supply
  • IBDP
    • Changing population >
      • Global patterns of economic development
      • Physical and human factors affecting global population distribution
      • Case study 1: China
      • Case study 2: Niger
      • Demographic transition
      • Megacity growth
      • Forced migration and internal displacement
      • Ageing populations
      • Pro-natalist and anti-natalist policies
      • Gender equality policies
      • Trafficking policies
      • The Demographic Dividend
    • Global climate vulnerability and resilience >
      • Atmospheric system
      • The energy balance
      • Changes in the energy balance
      • The enhanced greenhouse effect
      • Climate Change and the Hydrosphere, Atmosphere and Biosphere
      • Impacts of climate change on people and places
      • Disparities in exposure to climate change risk and vulnerability
      • Government-led adaptation and mitigation strategies
      • Civil society and corporate strategies
    • Global resource consumption and security >
      • Progress towards poverty reduction
      • Measuring trends in global consumption
      • Global patterns and trends in the availability and consumption of water
      • Global patterns and trends in the availability and consumption of land/food
      • Global patterns and trends in the availability and consumption of energy
      • Water food and energy nexus
      • Recycling and waste
      • Malthus vs Boserup
      • Resource Stewardship strategies
      • Sustainable Development Goals
    • Freshwater - drainage basins >
      • The drainage basin as a system
      • How rivers change from source to mouth
      • River discharge
      • River processes
      • River landforms
      • Factors affecting flood risk
      • Attempts at flood prediction
      • Flood mitigation
      • Flood mitigation case studies
      • Water scarcity
      • Agricultural activities and water quality
      • Pressures on lakes and aquifers
      • Internationally shared water and conflict
      • Water management: participation of local communities
      • Dams as multi-purpose schemes
      • Water management: Integrated Drainage Basin Management (IDBM)
      • Managing wetlands
    • Leisure, Sport and Tourism >
      • Growth and purpose of leisure time
      • Categories of tourism and sport
      • Economic development and participation
      • Factors affecting personal participation
      • Factors affecting growth of tourism hotspots
      • Spheres of influencee
      • Factors affecting a national sports league
      • Festivals
      • Niche national tourism strategies
      • Role of TNCs
      • Tourism as a national development strategy
      • International sporting events
      • Consequences of unsustainable growth
      • Sustainable tourism
      • Future international tourism
      • Political and cultural influences on sport
    • Extended Essay in Geography >
      • Supervisor meetings
    • Skills/concepts >
      • Infographics
      • 4 Ps
      • Mock examination revision and preparation
  • Geography and ToK
  • Theory of Knowledge
    • Knowledge and Technology
    • Knowledge and Language
    • Knowledge and Politics
    • Knowledge and Religion
    • Knowledge and Indigenous Societies

Measuring Earthquakes

Why measure earthquakes?

Measuring earthquakes is important for a range of reasons. These include:
  • to allow seismologists and other scientists to develop their understanding of earthquakes and their causes.
  • to allow us to make meaningful comparisons between earthquakes to make planning and risk assessment more meaningful and effective.
  • to help evaluate the effectiveness of earthquake management.

How to measure earthquakes

The Richter Scale is probably the best known scale for the measurement of earthquakes but today it is rarely used as it has been replaced by other measures which are more accurate and/or useful.

We can measure earthquakes using two possible approaches:
  1. How intense was the earthquake? - this approach considers the amount of movement and the sheer energy that the earthquake released. For this we use the MOMENT MAGNITUDE SCALE.
  2. What effects did the earthquake have? - this approach looks at the damage that the earthquake caused when it occurred. For this we use the MERCALLI SCALE.

The Moment Magnitude Scale

The Moment Magnitude Scale measures the amount of energy released by an earthquake event. It is calculated using a formula that  includes the rigidity of the rock affected, the distance moved and the size of the area where movement takes place. The video on the left below explains this more fully.
As the size of an earthquake increases on the Moment Magnitude Scale, the amount of energy increases logarithmically. This means that an earthquake that each magnitude releases approximately 32 times more energy than the magnitude below it. So, an earthquake of Mw 7.0 releases about 32 times as much energy as one of 6.0 and 1,000 times that of 5.0! Watch the video clip below and study the graph to understand this more fully.
Picture

The Mercalli Scale

The Mercalli Scale takes a different approach. Instead of scientifically measuring the amount of energy released by an earthquake, the Mercalli Scale focuses on the effects that an earthquake has on people and the environment. It is expressed using Roman numerals, from I to X as below:
Picture
Picture

Measuring earthquakes - tasks

  1. In your own words describe what the Moment Magnitude measures. You should include all of the following terms in your answer: energy, area, rigidity, movement, rock
  2. What is meant by a logarithmic scale? Why is it important to understand this when using the Moment Magnitude Scale?
  3. Make sure you have a copy of the Moment Magnitude Scale stuck into your book.
  4. What are the limitations of the Moment Magnitude Scale for someone studying the impacts of earthquakes?
  5. What does the Mercalli Scale measure? How is this different from the Moment Magnitude Scale?
  6. Create a “cartoon”/illustrated guide to the effects at the different levels of the Mercalli Scale. You can do this by hand or you could use IT with a website like one of those below.
  7. What would be the advantages of the Mercalli Scale to the leaders of a relief organisation? What would be its limitations for a seismologist?
Storyboard That
Strip Creator
Toondo (registration needed)
  • Home
    • Contact
  • MYP
    • Development >
      • An unequal world?
      • Billionaires investigation
      • Africa: the danger of a single story
      • Patterns of development
      • Trade and development
      • Fair Trade
      • Sustainable Development Goals
    • Tectonic Hazards >
      • What is risk?
      • Alfred Wegener and Continental Drift
      • Plate tectonics
      • Distribution of tectonic hazards
      • Measuring earthquakes
      • Why do people die in earthquakes?
      • School earthquake plan
      • Earthquake assessment
      • Volcanoes - what are they? Why are they important?
      • Volcano "Science Fair"
      • Causes of tsunami
    • Population >
      • Why study population?
      • Population distribution
      • Population growth
      • Population pyramids
      • Demographic transition model
      • Migration
      • Migration examples - case studies
      • Refugees in Indonesia
      • Population revision activities
    • Weather and Climate >
      • Weather vs Climate and why is it important?
      • Climate graphs
      • Why does it rain?
      • What affects temperature and why is Jakarta so hot and wet?
      • What causes wind and how do we measure it?
      • Microclimates
  • IGCSE
    • Course information
    • Physical: Hazardous environments >
      • Distribution of tectonic hazards
      • Causes of tsunami
      • Measuring earthquakes
      • Earthquake case study 1: Haiti
      • Earthquake case study 2: Christchurch
      • Why do earthquakes do more damage in LICs than in HICs?
      • How are volcanic eruptions measured?
      • Tropical storms - distribution
      • Causes of tropical cyclones
      • Tropical cyclones - case study
      • Why live in hazardous areas?
    • River Environments >
      • Hydrological cycle
      • River basins
      • Factors affecting river regimes
      • Fluvial processes: erosion
      • Fluvial processes: weathering and mass movement
      • Fluvial processes: transportation and depositon
      • River features and their formation
      • How rivers change from source to mouth
      • Uses of water
      • Water pollution
      • Water supply
  • IBDP
    • Changing population >
      • Global patterns of economic development
      • Physical and human factors affecting global population distribution
      • Case study 1: China
      • Case study 2: Niger
      • Demographic transition
      • Megacity growth
      • Forced migration and internal displacement
      • Ageing populations
      • Pro-natalist and anti-natalist policies
      • Gender equality policies
      • Trafficking policies
      • The Demographic Dividend
    • Global climate vulnerability and resilience >
      • Atmospheric system
      • The energy balance
      • Changes in the energy balance
      • The enhanced greenhouse effect
      • Climate Change and the Hydrosphere, Atmosphere and Biosphere
      • Impacts of climate change on people and places
      • Disparities in exposure to climate change risk and vulnerability
      • Government-led adaptation and mitigation strategies
      • Civil society and corporate strategies
    • Global resource consumption and security >
      • Progress towards poverty reduction
      • Measuring trends in global consumption
      • Global patterns and trends in the availability and consumption of water
      • Global patterns and trends in the availability and consumption of land/food
      • Global patterns and trends in the availability and consumption of energy
      • Water food and energy nexus
      • Recycling and waste
      • Malthus vs Boserup
      • Resource Stewardship strategies
      • Sustainable Development Goals
    • Freshwater - drainage basins >
      • The drainage basin as a system
      • How rivers change from source to mouth
      • River discharge
      • River processes
      • River landforms
      • Factors affecting flood risk
      • Attempts at flood prediction
      • Flood mitigation
      • Flood mitigation case studies
      • Water scarcity
      • Agricultural activities and water quality
      • Pressures on lakes and aquifers
      • Internationally shared water and conflict
      • Water management: participation of local communities
      • Dams as multi-purpose schemes
      • Water management: Integrated Drainage Basin Management (IDBM)
      • Managing wetlands
    • Leisure, Sport and Tourism >
      • Growth and purpose of leisure time
      • Categories of tourism and sport
      • Economic development and participation
      • Factors affecting personal participation
      • Factors affecting growth of tourism hotspots
      • Spheres of influencee
      • Factors affecting a national sports league
      • Festivals
      • Niche national tourism strategies
      • Role of TNCs
      • Tourism as a national development strategy
      • International sporting events
      • Consequences of unsustainable growth
      • Sustainable tourism
      • Future international tourism
      • Political and cultural influences on sport
    • Extended Essay in Geography >
      • Supervisor meetings
    • Skills/concepts >
      • Infographics
      • 4 Ps
      • Mock examination revision and preparation
  • Geography and ToK
  • Theory of Knowledge
    • Knowledge and Technology
    • Knowledge and Language
    • Knowledge and Politics
    • Knowledge and Religion
    • Knowledge and Indigenous Societies